It has issued notice to the chief secretary and the director general of police of Uttar Pradesh, seeking a detailed report, including action taken against the "delinquent police officials", who refused to register an FIR.
"The NHRC also expects from the DGP, an explanation for not communicating the custodial death to the commission within 24 hours. All the reports, including health screening report of the deceased at the time of his admission in the jail and medical treatment provided by the jail authorities, are to be sent," the rights panel said in a statement.
They have been given four weeks to respond, it said.
The commission said it has also directed the chief secretary to "look into the matter personally and ensure that the aggrieved family is not subjected to further harassment and humiliation by the opponents who appear to be resourceful persons of the locality".
"He (chief secretary) is also directed to monitor and expedite the magisterial inquiry which is underway," it added.
The man, aged around 50, was rushed to a hospital from the district jail on April 8 night and died during treatment yesterday, an officials said. He was arrested on April 5 under the Arms Act, they added.
Significantly, a case had been registered against four persons a few days ago on a complaint by the wife of the deceased that he was beaten up.
Under fire, Chief Minister Adityanath has sought a report into the custodial death.
The Unnao SP yesterday said six policemen, including SHO, Makhi, Ashok Kumar Singh, an outpost in charge and four beat constables had been suspended.
UP Director General of Police O P Singh said a Lucknow Police team had been constituted to probe the entire matter.
The recent immolation bid by the woman was foiled by the police. She had alleged that the Unnao police had not registered a case against the BJP MLA despite her complaint and no action was taken, police said.
Sengar represents the Bangermau constituency in Unnao district, and has denied the charge. He also demanded a high-level inquiry and sought action against those guilty.
"After medical examination, the woman's father was sent to prison," the NHRC said.
According to media reports, on April 8, in the evening, he complained of stomach ache and the next day he died in the hospital at around 3.30 am, the NHRC said.
"According to media reports, the doctors, who examined the deceased after he spent two days in police custody, noted 19 injury marks. The news report also states that he was taken to hospital only when his condition deteriorated," the rights panel alleged.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)